Water-circulating device.



PATENTED DEC. 19, 1905.

M. H. VOIGT.

WATER GIROULATING DEVICE.

APPLICATION FILED JAN.28.1905.

UNITED STATES PATENT FFIGE.

WATER-CIRCULATING DEVICE.

Specification of Letters Patent.

Patented Dec. 19, 1905.

Application filed January 23, 1905. fierial No. 242,434-

To all whom it may concern.-

Be it known that I, MARTIN HENRY VOIGT, a subject of the German Emperor, and a resident of Kleefeld, near Hanover, in the Kingdom of Prussia and Empire of Germany, have invented a new and useful Improvement in Water-Circulating Devices for Flue-Boilers and the Like, of which the following is a specification.

My invention relates to improvements in flue-boilers, as of the Lancashire or the Cornish type, in which the combustion takes place in tubes surrounded by water; and the objects thereof are, first, to facilitate and increase the proper and useful circulation of the water about and around the heating-surface of the flues mentioned and in the waterspace of the boiler generally, and, second, to increase the generation of steam and to facilitate its free and unimpeded escape from the upper surface of the main body of the water in the boiler. I attain these objects by the device illustrated in the accompanying drawings, in which Figure 1 is a transverse section showing a part of the cross-section ofthe boiler-shell and its steam and water spaces, together with a cross-section of one of the flues and of the circulation device thereto belonging. Fig. 2 is a perspective view of part of one of the flu es, together with the thereto-belonging circulation device.

Similar letters refer .to similar parts throughout the description and the drawings.

The heretofore known and used water-circulation devices used in connection with steamboilers and in which an increased circulation of the water is attempted to be attained by means of a current of steam generated in the boiler itself for the purpose of driving the water from the lower levels upward or sidewise and upward have the disadvantage that, in the first place, the force necessary to cause such circulation is by far too weak, and, in the second place, the steam is compelled to press through narrow or confined and sometimes tortuous tubes, nozzles, or passages, which not only occasion excessive friction, with consequent loss of effect, but also are easily clogged by incrustations or by other foreign bodies. Such disadvantages can be so considerable as fully to neutralize all advantages which might otherwise be attained by the use of such auxiliary devices. The

herein described and illustrated invention is caps Z) and 0, each of which lies upon and fits closely to a flue and also fits steam tight against its neighbor or companion in the pair, while one in each .pair is furnished with a preferably funnel-shaped upward-trending lateral throat or outlet d. Each of these hoods has a steam-space, as e and f, as a reservoir for the steam generated from the surface of the flue 9, one of such spaces a being for the suction and the other or companion space f for the forcing action of the steam.

By means of the continuous generation of steam from the heating-surface g the waterlevel under the steam-space f is kept down to the level of the lateral outlet of such space, and there results, by means of the pulsating forward-driving action of the outer steam, a forcing out of separate bubbles or other masses of steam, which carry therewith a current of Water. The steam thus forced out fills the chamber a, from which latter it passes further into the throat or passage (Z. The bubbles or other masses of steam issuing from the steamchamber a impart their velocity to the water in the throat or passage d, where they are pressed out flat, and thus effect an intensified accompanying current of the water. By this means allunnecessary friction of the steam against the walls of the throat or passage (Z is avoided, and at the same time there is produced an increased current of water carried along by friction with the steam.

In the narrow passage-way formed between the upper surface of the flue g and the lower edges of the adjacent walls of the two hoods there is a longitudinal strip of metal h, preferably curved in cross-section, as shown, in order to give it more stiifness'and to direct the steam and water currents more practically, although I reserve the right to employ any other suitable cross-section or even to omit such strip. WVhere I use it, the effect is to inscribed offers an opportunity of preventing the attachmentof scale or the deposition of mud upon the outer surface of the flue, as the heavier solid particles in the water have, by reason of the accelerated velocity under the hoods e f and in the throat or passage (Z, no time to attach or deposit themselves on the hot surface of the flue, but are carried over and across and can only drop in some quiet portion of the water-space of the boiler, where their presence will be harmless and their rehigher level than the lower edge of the partition-wall and the outer edges of the hoods.

2. In a flue-boiler a water-circulating device comprising a parallel pair of concave hoods above the upper heating-surface of the flue, said hoods open below for the inlet of a watercurrent and divided from one another by a longitudinal downwardly-dependent partitionwall, a lateral throat serving as outlet for the mingled current of water and steam from one of said hoods, said throat being below the level of the summits of the hoods but at a higher level than the lower edge of the partition-wall and the outer edges of the hoods a longitudinal strip of metal in the passage between the upper'surface of the flue and the lower edge of the partition-wall saidstrip of metal being of double-curved cross-section.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

MARTIN HENRY VOIGT. Witnesses:

LEONORE RASOH, ANNA DIPPEL. 

